<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>引出生命周期</title>
    <script src="../js/vue.js"></script>
    <script src="../js/阻止vue在启动时生成生产提示.js"></script>
</head>

<body>
    <div id="root">
        <h2 :style="{opacity}">欢迎学习Vue</h2>
    </div>

</body>
<script>
    const vm = new Vue({
        el: "#root",
        data: {
            opacity: 1
        },
        methods: {
            
        },
        //Vue完成模板的解析并把初始的真实DOM元素放入页面后(挂在完毕)调用mounted
        mounted() {
            console.log('mounted');
            setInterval(()=>{
            this.opacity -=0.01
            if(this.opacity <= 0 )
            this.opacity = 1
    },16)
        },
    })
    // 通过外部定时器实现(不推荐)
    /* setInterval(()=>{
        vm.opacity -=0.01
        if(vm.opacity === 0 )vm.opacity = 1
    },16) */
</script>

</html>